AUTHOR=Liang Zihong , Chen Junjie , Xu Zhaopeng , Chen Yuyang , Hao Tianyong TITLE=A Pattern-Based Method for Medical Entity Recognition From Chinese Diagnostic Imaging Text JOURNAL=Frontiers in Artificial Intelligence VOLUME=Volume 2 - 2019 YEAR=2019 URL=https://www.frontiersin.org/journals/artificial-intelligence/articles/10.3389/frai.2019.00001 DOI=10.3389/frai.2019.00001 ISSN=2624-8212 ABSTRACT=Background: The identification of medical entities and relations from electronic medical records is a fundamental research for medical informatics. However, extracting valuable knowledge from these records is a challenging work due to its high complexity. The accurate identification of entity and relation is still an open research problem in medical information extraction. Methods: A pattern-based method for extracting certain tumor related entities and attributes from Chinese unstructured diagnostic imaging text is proposed. This method is a composition of three steps. Firstly, an algorithm based on keyword matching is designed to obtain the primary sites of tumors. Then a set of regular expressions is applied to identify primary tumor size information. Finally, a set of rules is defined to acquire metastatic sites of tumors. Results: Our method achieves a recall of 0.697, a precision of 0.825 and an F1 score of 0.755 using an overall weighted metric. For each of extraction tasks, the F1 scores are 0.784, 0.822 and 0.740, respectively. Conclusions: The method is proved to be stable and robust with different amounts of testing data. It achieves a comparatively high performance in CHIP 2018 open challenge, demonstrating its effectiveness in extracting tumor related entities from Chinese diagnostic imaging text.